Ive been brewing for 5 years and have never heard of a carboy exploding, though in my lurking days, I remember reading a story about a guy who lost his brother from sliding into a carboy filled with loose change. The carboy exploded and severed his femoral artery. The brother was dead in a minute or two.

With that story in mind, I'd probably lose that clamp. Bungs will blow out before anything explodes, but I'm not so sure about the clamp.

You might be confusing the story. The brother did die, but he tripped over a carboy, shattering it. He did die the way you described.

I just kegged an Amber ale that never had any airlock activity... the bucket lid was not on all the way. Brewed up just fine. The pressure all went out of the bucket lid where it didn't seal.. I've also had fermentations blow the lid off the bucket. Just put it back on with a blowoff tube, and back to fermenting.

Nothing to worry about at all. Just makes a mess if it blows. This hobby shouldn't make you paranoid... where's the fun in that? Just remember... you're making beer, not nuclear fusion.

This may not apply to homebrew scale, with less osmotic pressure, etc., but I would want the cap or stopper to blow out rather than take any chance of the carboy shattering. You don't need that tight of a seal with the cap- if it's the proper size, it should be rather snug.

I do a blowoff with all higher gravity brews, even temp controlled.

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Give a man a beer, waste an hour. Teach a man to brew, and waste a lifetime! Bill Owen quote

I wouldn't use a glass carboy for primary unless there was a blow off tube. I don't think it's a safe thing to play with that thick of glass with pressure. Plus you need to make sure you have a big enough carboy, like are you using a 5 gal carboy for a 5 gal batch or a 6.5 carboy? That headspace makes a big difference. I wouldn't trust anyone that says "your carboy won't explode". All that means is that it hasn't happened to them, not that it can't happen.

I was thinking about this today due to getting my new big mouth bubbler fermentor. Its a 6.5 gallon and the krausen from my fermenting brown ale is almost up to the top in day 3. I don't have a blow off tube to fit yet but made other arrangements. Reason I was kind of worried is because it has a threaded top that screws on, not a typical bung and airlock. I doubt this would blow off before the glass breaks. I ended up just putting the airlock cap sitting on top without screwing it down just in case.